This invention relates generally to injection molding and more particularly to injection molding apparatus where the forward end of a heated probe has at least one conical tip which extends outwardly at an angle into a conical recess leading to the gate.
Heated probes which have pointed tips and are mounted to extend into an injection molding melt passage are well known in the art. For instance, the applicant's U.S. Pat. No. 4,820,147 which issued Apr. 11, 1989 discloses a heated probe which extends through sleeve seated in a cavity plate. The applicant's Canadian patent application serial number 2,032,728 filed Dec. 19, 1990 entitled "Injection Molding Probe with Varying Heat Profile" shows providing the electrical heating element of such a probe with different numbers of multiple runs along its length. The applicant's Canadian patent application serial number 2,037,186 filed Feb. 28, 1991 entitled "Injection Molding Probe with a Longitudinal Thermocouple Bore and Off Center Heating Element" relates to similar apparatus in which the heating element is relocated and a thermocouple bore is provided. However, these previous probes all have the disadvantage that the pointed tip only extends forwardly along the central axis.
Heated nozzles having pointed tips are also known in the art. While the applicant's U.S. Pat. No. 4,768,945 which issued Sept. 6, 1988 does show a nozzle with an angled tip for edge gating, it extends at a shallow angle to the central axis. Mold-Masters Limited brochure E-CMSSN-11-90 entitled "Injection Molding with Compact Master-Shot Single Nozzle Hot Runners" published November 1990 similarly shows on page 17 a nozzle having a single angled tip for hot tip gating. In addition to being a nozzle and not a probe, it is restricted to a single gate.